SWR!

[Falkon MX-5]

Okay, first I wanna make sure I did this right. I borrowed a friend's SWR meter, because I calibrated with my other friend's meter, and it's junk. So I'm using a Dosy meter, I set the SWR calibration, I switch to SWR test, key down, then my friend said to whistle in, so I did. 1.6 is the LOWEST I could get it on channel 1, and about 2.8 is the lowest it went on 40! I tried EVERYTHING! Is this Wilson antenna just junk? I adjusted the antenna, ground a total of about 1/2" off and it just wouldn't get any better.

[Big Hit]

When testing your SWR, don't whistle in the mic, in fact turn the mic gain all the way down. You test your SWR when you dead key the mic with no modulation.

[Falkon MX-5]

ERG! This guy has been on the radio for decades and he told me the wrong thing! I bet I ground the wilson down too much now!

[231]

Yep...and also sounds like the antenna stinger could use adjustment and/or trimming.

[Mr RadioActive]

What kinda wilson is this? Wheres it located? Coax length? Sorry if I missed all this in another post. Big Hits right, never whistle into the mic when testing SWRs

[Falkon MX-5]

Wilson 1000, bought from you, standard 18 ft. coax the antenna came with.

I retested the SWR the proper way, and I absolutely can not get it below about 1.4:1 on 40 and 1.1 to 1.15 on 1. I did end up cutting more off the whip, but it got to a point where it started to hurt the swr, so I raised it a bit, and that's the best it will do. I checked my hinges on the trunk, and there's no sort of spacers or washers preventing contact. I think maybe if I unbolt the trunk lid and sand down the areas where the hinges contact it will help, but I don't want it to rust.

Is there any other way to get better SWR on 40?

[231]

Is there any other way to get better SWR on 40?

Remove the stinger and trim about 1/4" off it. Re-install it and try again. Your antenna stinger is just a tad too long. That would be normal though. The band range of most production antennas is such that it can be tuned for downstairs and upstairs. You have acceptable SWR's now, but if you plan on ever using it for 10 meters, you'll need to trim more than I mentioned. Normal tuning stuff though.

[Falkon MX-5]

I was trimming it down. It got to a point where SWR actually went up after I trimmed, and I had to adjust it out a bit.

[Mr RadioActive]

If your swrs are higher on 40 then one, its gotta get shorter. Higher freqs take smaller antennas, and your higher freq is not tuned.

[Falkon MX-5]

I really just don't see the SWR getting better on the meter while shortening it. It's like I've gotten to a point of diminished returns.

[231]

I know this sounds silly, but after trimming, did you hit the stinger with a wire wheel or file or something to remove any burs? I've had plenty of times over the years where we didn't have that, and the stinger wasn't bottoming out. They can hang just a bit giving the illusion they are bottomed out...when in fact they are not. I usually hit them with a quick grind wheel myself to insure this doesn't happen.

It just sounds odd that your SWR's are so low on lower channels, but not adjusting on the higher ones. If you are convinced that it's a grounding issue, then by all means follow your conscience on that. No such thing as too much grounding. I just find it very odd indeed.

Just a couple thoughts.

[Falkon MX-5]

yeah, thanks man! I'm skiddish of grinding TOO much off. It's sitting at about 1.4:1 on 40, but I figure I should try grinding a little bit more off.

I definately deburr the end after I grind it down. I don't make the antenna hit bottom, I always adjust it out about 1/8" from the very bottom. Is it better to contact it to the bottom?

[231]

Shouldn't make any difference at all whether you bottom it out or not.

[Mr. 9k9]

First thing that comes to my mind is that you are in a Miata. #1 I'm guessing that in a small car like that you have much more coax then you need. Do you have the excess coax coiled up at all? If the coax is coiled up you will see incorrect readings. #2 I'm wondering if the fact that the car is a convertible is having an effect. I know it is important for the car to be turned off with the windows up. I would guess that these are your 2 biggest issues.
DJ

[Falkon MX-5]

It's not a big deal, since the soft top frame would make the same sort of cage that a hard top would. That's why it's impossible for me to use a handheld inside the car.

[Mr. 9k9]

What about the excess coax cable? Is it coiled up?
DJ

[Falkon MX-5]

There isn't THAT much excess, because going from the front of the car to the rear, I have all the cable hidden and running under carpet. There's about 3ft or so extra and it's not really coiled.

I doubt it would be making a lot of inductance there, since it's not really coiled.